Thionophosphoric acid esters



THIONOPHOSPHQRIC ACID ESTERS August Diirken, Wuppertal-Sonnborn, and Gerhard 'Schrader, Wuppertal-Cronenberg, Germany, assignors to Farbenfabriken Bayer Aktiengesellschaft, Leverkusen, Germany, a corporation of Germany N Drawing. Filed Apr. 1, 1958, Ser. No. 725,495

Claims priority, application Germany Apr. 15, 1957 13 Claims. (Cl. 260-461) The present invention relates to and has as its objects thiophosphoric acid esters and a method of producing same. Generally the new esters of the present invention correspond to the following formula RCHON s OR ll/ OP\ in which R stands for a lower alkyl radical especially v suchones up to 4 carbon atoms, and R stands for hydrogen, alkyl or aryl radicals.

It has been found that highly active insecticidal thionophosphoric acid esters are obtainable by reacting a-hydroxy carboxylic acid nitn'les with 0.0-dialkyl-thionophosphoric acid chlorides as may be shown by the following equation:

atent Useful acid bindacid nitrile, then hydrocarbons such as benzene or toluene.

The reaction is expediently carried out at elevated temperatures.

The compounds of the present invention are generally valuable insecticides and plant-protecting agents. They kill pests such as aphids, flies and mites and exhibit a very remarkable systemic action. Most remarkable is the action against flies. The application of these compounds should be carried out according to the use of other known phosphor insecticides, i.e. in dilution or solution with solid or liquid carriers such as chalk, talc, bentonite, water, alcohols, liquid hydrocarbons etc. The inventive compounds may further be used in combination with other known insecticides or pesticides, etc. Efiective concentrations of the compounds may vary also, generally, concentrations of 0.0001% to 1.0% kill pests effectively. The combinations of the compounds may be sprayed or dusted or otherwise brought in contact with pests or plants to be protected. They may also be used as aerosols.

Patented Nov. 15,. 1960 As an example for the special utility of the inventive compounds the compounds of the following formulae have been tested against fiies (Drosophila) and spider mites (Tetranychus telarius=two-spotted spider). Aqueous solutions of the aforementioned compounds have been prepared by admixing them with the same amount of an auxiliary solvent (acetone). A commercial emulsifier (benzyl hydroxy diphenyl polyglycol ether) is added in an amount of 20% referred to active ingredient. This premixture then is diluted with water to the desired concentration.

The tests have been carried out in the following manner:

(A) Against flies (Drosophila). in Petri dishes of aboutS inches'diametenfilter paperihas been placed, which has been wetted with aqueous solutions of the above shown active ingredients prepared as indicated above. About 30 flies have been placed under the coveredPetri dishes and the living status has been determined afiter 24 hours. The following killing rate has been obtained:

(I) Solutions of 0.0000=1% kill flies to (II) Solutions of 0.001%kill flies to 100%,

(B) Against spider mites (contact-insecticidal action). Bean plants (Phaseolus vulgaris) of about 15 inches hight are spread drip wet with 0.l% solutions prepared as indicated above. The bean plants have been infested heavily with the two-spotted spider (Tetranychus telarius). Evaluation has been carried out after 24 hours, 48 hours and 8 days. The total percentage of killed pests after 8 days is as follows:

(I) Solutions of 0.1% kill spider mites 100%, (II) Solutions of 0.001% kill spider mites 50%.

The following examples are given by way of illustration only without, however, limiting the present invention thereto:

Example 1 24 grams of u-hYdIOXYPI'OPiOIliO acid nitrile (Houben- Weyl VIII, 277) are mixed with 63 grams of diethylthionophosphoric acid chloride. This mixture is added dropwise with stirring and cooling at 30 C. within about 15 minutes to 27 grams of anhydrous pyridine and the whole is then heated to 4550 C. for a further 4 hours. The mixture is then diluted with 100 millilitres of methylene chloride and the solution thus obtained is poured onto 200 grams of ice to which 15 millilitres of concentrated hydrochloric acid has been added. The methylene layer is separated, washed twice with 25 millilitres ertions of water and then dried over sodium sulfiate. After filtration, the solvent is distilled 011 under vacuum. 33 grams of a colorless oil remain which distills at 57-58 C./ 0.01 mm. Hg. Yield 44% of the theoretical.

Calculated for mol 223.2:

P 13.9%, S 14.4%, N 6.25%. P 14.0%, S 14.9%, N 6.13%.

5 LD on rats orally: 100 nag/kg. I i

0.00001% solutions kill flies to 100%. Spider mites Calculated for mol 285.3: are killed to 100% with 0.1% solutions. P 10.8%, S 11.2%, N 4.9%. By exactly the same way there may be obtained the P 10.8%, S 11.1%, N 4.6%. esters of the following formulae: LD on rats orally: mg./kg.

CHIO s a By the same way there may be obtained the esters of the following formulae: 1 CHaO 3H; fi isoC:H1O\fi I 10 /PO-EH /P O ?H CN OHIO N iSoCsH7O on, fi

notn1o zs 1 P O CH CN CzH'IO CN 110.1110 om Example 4 Example 2 fi 021350 3 P-O-OH-CN POOHr-CN (mm CZHEO 34.5 grams of a-hydroxybutyric acid nitrile (B.P. 79

C./5 mm. Hg) are mixed with 76 grams of diethyl thiono- 23 grams of glycohc and mm1e (GA 11101) are surfed phosphoric acid chloride. To this mixture there are added with 76 grams of diethyl thionophosphoric acid chloride 25 dropwise with Mining and cooling 33 grams of anhyand treated with grams P Y PY at drous pyridine at about C. within'S minutes. The 29-250 wh'ilst Vlgorously The mlxture is mixture is after-stirred at 40-45 C. for 8 hours, treated, surfed at for another 6 hours and allowed to after cooling with 100 millilitres of methylene chloride stand at room temperature for 2 days. The pvn m and washed with ice water to which 15 millilitres of conhydmchlonde thus formed removed y filtmnon; The 30 centratcd hydrochloric acid had been added. The sepfilltl'ate Poured Onto 100 grams of we to Whlch 15 arated organic layer is washed twice with small quantities millilitres of concentrated hydrochloric acid has been f water until neutral, dried over Sodium lf t and the added- The is treated with 60 m'flhhtres solvent is then distilled ofi under vacuum. The residue Ylene chloride, Shaken and the methylene layer 13 is distilled under high vacuum. 37 grams of the new arated from water. The methylene chloride solution is ester are obtained as a clear pale yellow oil, y 62460 dried over sodium sulfate. Sodium sulfate is then filtered mm. Hg Yield 3 9% f the theoretic off and the solvent is removed by distillation under vac By exactly the Same Way there may be obtained w uum. 51.2 grams of the new ester of HP. 6264 C./ 0.01 ester f the f ll i formula mm. Hg are obtained as a water-insoluble colonless oil.

Yield 61.5% of the theoretical. 40 CHa0\fi Calculated for mol 209.2: P 14.9%, S 15.4%, N 6.7%. C1150 02115 P 15.0%, S 15.8%, N 6.4%. We claim; L135 on rats orally: 100 1. Thionophosphoric acid esters of the formula By exactly the same way there may be obtained the CN esters of the following formulae:

s OR CHO s 3' i OCH CN on CHsO C H O 5 wherein R stands for a lower alkyl radical having up to a 7 u 4 carbon atoms, and R stands for a member selected /PO CHT'CN from the group consisting of hydrogen, a lower alkyl CaH70 radical having up to 4 carbon atoms and a phenyl radical. Example 3 2. The thionophosphoric acid ester of the following fi formula C2H50 s (EH50 8N i O-0HCN To a mixture of 34 grams of freshly distilled mandelic 0,13 0 CH3 acid nitrile and 47 grams of diethyl thionophosphoric acid monochloride there are added dropwise with stirring and The 'thlonophosphonc acld ester of the fOHQWmE cooling 21 grams of pure pyridine within 20 minutes. The formula mixture is then heated to 30 C. for another 16 hours. 01130 s The reaction product is diluted with 60 millilitres of methylene chloride and poured onto 100 grams of ice CH 1 to which 15 millilitres of concentrated hydrochloric acid had been added. The methylene chloride solution is sep- 4 The thionophosphoric acid ester of the following arated and dried over sodium sulfate. Upon distilling formula off the solvent 61.5 grams of the new ester are obtained as a pale yellow water insoluble oil. The ester can be fi distilled under vacuum with decomposition only. Yield P Of the theoretical. "5 c o CH3 6 5. The thionophosphoric acid ester of the following 10. The thionophosphoric acid ester of the following formula formula nCzHzO s fi \n P-O-GHQ POCH--CN nCsH'IO H; 6 611,0 ON 11. The thionophosphoric acid ester of the following 6. The thionophosphonc 301d ester of the followmg f l formula C \fi 021x60 s P-O-CH 10 Q I E OCHr-CN CsH70 JJN CzHsO 12. The thionophosphoric acid ester of the following 7. The thionophosphoric acid ester of the following formula 02350 S formula 15 l OGHCN CHIO S i -o-cn ON 13. The thionophoshoric acid ester of the following CHQO formula 8. The thionophosphoric acid ester of the following 20 d? formula /POCHCN CaHrO S CHsO 2H5 \Il /P O OH' CN References Cited in the file of this patent 25 UNITED STATES PATENTS The thionophosphofic acid ester of the following 2,494,283 Cassaday et a1. Jan. 10, 1950 formula 2,494,284 Cassaday et a1. Jan. 10, 1950 c,11,o\fi 2,829,111 Schrader Apr. 1, 1958 r-o-cn so FOREIGN PATENTS 011110 (SN 1,024,509 Germany Feb. 20, 1958 UNITED STATES PATENT OFFICE QERTIFICATION 0F CORRECTION Patent No, 2,960,525 November 15 1969 August Do'rken et all,

It is hereby certified that error appears in the aboent requiring correction and that th ve numbered pats said Letters Patent corrected below.

should read as Column 3, line 24, for "and" read acid Signed and sealed this 30th day or" May 19610 (SEAL) Attest:

ERNEST W. SWIDER DAVID L. LADD Attesting Officer Commissioner of Patents 

1. THIONOPHOSPHORIC ACID ESTERS OF THE FORMULA 